As observed for primary tumour cells, upregulation of MMP-3 and S100a8 was also found in the in vitro comparisons of both 67NR/4T1.2 and EO771/EO771.LMB (supplementary material Fig. S12), indicating that expression of these genes in tumours is regulated in a cell autonomous way and that tumour epithelium might be the major site of expression in vivo. Here, MMP3 is linked to neoplasm.